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Military vision
The U.S. military also
depends on China's
mines. Night-vision
goggles (above) require
lanthanum, gadolinium,
and yttrium. Samarium
magnets, which can
withstand intense heat,
help control Predator
drones and Tomahawk
cruise missiles.
Medical scans
Gadolinium also
serves as a contrast
agent in magnetic
resonance imaging,
or MRI, helping
surgeons distinguish
diseased from healthy
tissue. In the scan at
right it highlights a
brain tumor (colored
orange for clarity).
Green machines
Hybrid cars would not
exist without rare earth
elements---lanthanum
for their batteries,
neodymium magnets
for their electric motors.
A wind turbine may
contain hundreds of
pounds of neodymium;
a compact fluorescent
lightbulb, much smaller
amounts of yttrium
and terbium.
And much else...
such as protecting eyes
and beverages from
ultraviolet radiation.
Praseodymium, erbium,
and neodymium tint
sunglasses; cerium
in wine-bottle glass
promotes absorption
of UV light. Some
power tools rely on
neodymium or dyspro-
sium magnets to shrink
their motors.